Silicon is a material which is used more and more in the manufacture of micromechanical timepiece parts, in particular parts which remain connected to a silicon-based substrate on which they have been machined.
With respect to the metals or alloys which are used as standard for manufacturing micromechanical timepiece parts, such as toothed wheels, or components of the escapement, silicon has numerous advantages. It is a very hard material of very light weight which makes it therefore possible for it to have very reduced inertia and consequently to improve the efficiency. Silicon likewise makes it possible to produce complex or monobloc parts.
In order to improve or modify the properties of the silicon, it is known to deposit a layer of a suitable material over the silicon. Thus, in order to improve its tribological properties, diamond is deposited on the silicon, for example by a method of thin-film vapour phase deposition (CVD/PVD).
However these methods have a deposition rate which can prove to be too slow when the thickness of the deposited layer exceeds a few microns. In fact, the deposition rates in CVD machines for example being typically of the order of ten nanometres/minute, this technique is not generally used for the manufacture of a layer greater than a few microns.
It is therefore necessary to propose a method for manufacturing a silicon-based micromechanical timepiece part which makes it possible to achieve rapid deposition of thick layers of a suitable material on the silicon.